The present invention relates to a disc brake of a utility vehicle.
In generic disc brakes, a brake caliper surrounding a brake disc is mounted on a brake carrier fixed to the vehicle such that it is displaceable in and against a brake-application direction of the disc brake. During a braking procedure, the brake caliper here is displaced relative to the brake disc, wherein a reaction force is produced on the rear of the brake caliper. As a result of this reaction force on the rear of the brake caliper, both the brake pad on the brake-application side and the brake pad provided on the rear side of the brake disc are pressed against the brake disc, which generate a braking torque by means of friction after overcoming an air gap present between the brake disc and the brake pads. The displacement of the brake caliper takes place here by means of a brake-application device, which substantially has a piston rod of a pneumatically or electromotively or spring actuated brake cylinder (not shown) and a movable pivoted lever, whereof the force during a brake-application procedure is distributed via a bridge to two threaded rams which press the brake pad on the brake-application side against the brake disc.
The brake caliper here is displaceable relative to the brake carrier, perpendicularly to the friction surface of the brake disc, via sliding guides. To this end, two sliding guides are provided, which each comprise a guide bar which is screwed to the brake carrier and extends with play into a respective bore in the brake caliper, wherein the guide bars and the bores receiving them extend in the brake-application direction of the disc brake. Arranged in this bore in the brake caliper is a respective bearing or sliding element which ensures a low-friction displaceability of the brake caliper with respect to the brake carrier without a high loss of power.
One of the sliding guides here is formed as a fixed bearing with a low sliding play, whilst the other is formed as a floating bearing, in particular for compensating manufacturing tolerances, thermal expansion of the component and assembly tolerances.
However, the production of a disc brake having a fixed bearing and floating bearing formed in this way for mounting the brake caliper on the brake carrier is relatively expensive, in particular owing to the bores for receiving the guide bars having to be incorporated precisely in the brake caliper.
The object of the present invention is to develop an economically producible disc brake of the generic type whilst at the same time retaining the stationary and floating bearing concept.
This object is achieved by a disc brake according to embodiments of the invention.
The inventive disc brake of a utility vehicle has a brake carrier which is stationary on the vehicle side and partially surrounds a brake disc and a brake caliper which is arranged on the brake carrier and partially surrounds the latter. The brake caliper is displaceable relative to the brake carrier, perpendicularly to a friction surface of the brake disc, via sliding guides. A first sliding guide of the sliding guides is formed here as a fixed bearing and a second sliding guide of the sliding guides is formed as a floating bearing. At least the floating bearing is formed according to the invention as a sliding block guide having a guideway extending in the displacement direction of the brake caliper and a first guide element received in the guideway.
A substantial simplification of the construction of the floating bearing is achieved as a result of designing the floating bearing as a sliding block guide. The function of the fixed bearing and the floating bearing of the brake caliper bearing arrangement is split here, wherein the guidance of the brake caliper through the brake-application movement and the wear path is assumed by the fixed bearing. The floating bearing now assumes the function of vibration stabilization and holding down the brake caliper to prevent the brake caliper from swinging or pivoting open about the fixed bearing. Such a simplified floating bearing is notable in particular for the more economical production method.
Advantageous variant embodiments of the invention are described and claimed herein.
According to an advantageous variant embodiment of the invention, the first guide element is arranged on the brake carrier such that it extends parallel to the friction surface and the guideway is arranged on a part of the brake caliper.
In a second alternative variant embodiment, the first guide element is arranged on the brake caliper such that it extends parallel to the friction surface of the brake disc and the guideway is arranged on a part of the brake carrier. Both variant embodiments enable the use of a slide block guide instead of a slide bush known from the prior art for receiving a guide bar as a guide element. Also, although it is possible to form the guide element as a bar, it is not compulsory. A design of the first guide element as a pin or the like having a lateral surface serving as a sliding surface is also conceivable.
The first guide element extends particularly preferably in the direction of the longitudinal extent of the brake carrier. According to an alternative variant embodiment, the first guide element extends perpendicularly to the direction of the longitudinal extent of the brake carrier and parallel to the friction surface of the brake disc.
Both variant embodiments are notable for the simple assembly of such a guide element, for example on a lower side of the brake caliper, which faces the brake carrier, or on an outer side of a pad carrier horn of the brake carrier, which faces away from a pad shaft for receiving brake pads, preferably by screwing said guide element into a bore which is provided for this purpose and has an internal thread.
According to an advantageous variant embodiment, the guideway has sliding surfaces which are formed as mutually parallel-aligned inner surfaces of an elongated hole in which the first guide element is displaceable in the displacement direction of the brake caliper.
According to an alternative variant embodiment, the guideway has sliding surfaces which are formed as mutually parallel-aligned inner surfaces of an elongated groove which is open on one side in the sliding direction of the first guide element.
The introduction of such an elongated hole or the formation of an elongated groove in the brake carrier or in the brake caliper is possible in a simple and economical manner in particular in brake carriers or brake calipers formed as cast parts.
According to a preferred variant embodiment of the invention, a head piece reaching behind the guideway is integrally formed or mounted on an end face of the first guide element. This head piece effectively prevents the brake caliper and the fixed bearing from swinging or pivoting open.